Light PhD Seminar: Electrochemical and fluid dynamical characterization of ciliary epithelium physiology: a multiscale approach

Abstract:
The ciliary epithelium (CE) is the primary site of aqueous humor (AH) production, which results from the combined action of ultrafiltration and active ionic secretion. The modulation of ionic secretion is an important target for drug therapy in glaucoma disease, therefore it is fundamental to identify the main factors contributing to it.

Ion secretion is a mechanism involving different spatial scales, from the ionic transporter to the eye level. Thus, a mathematical model for AH production needs to take into account more levels. In this presentation, we aim to investigate two of them: cellular level and ion transporter level. In particular, we make the first steps into the electrochemical and fluid dynamical characterization of ciliary epithelium physiology at both scales.

At first, we review eye physiology, with emphasis on the mechanisms for AH production. Then, we present existing modeling approaches at the cellular and transporter levels that could be useful to derive new models. We derive a model for ion secretion at the cellular level studying a configuration of ion transporters across CE membranes. Thanks to this model we are able to characterize the electrochemical and fluid dynamical baseline of a couple of Pigmented and Non-Pigmented Epithelium cells. Finally, we show new modeling tools at the ion transporter level: from the 3D formulation of the Velocity-Extended Poisson-Nernst-Planck system of partial differential equations, we derive a 1D model through an averaging technique. Numerical simulations through a finite element formulation have been conducted to compare 1D and 3D models.

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